NFS: Fix O_DIRECT locking issues

The dreq fields are protected by the dreq->lock.

Fixes: 954998b6 ("NFS: Fix error handling for O_DIRECT write scheduling")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

fs/nfs/direct.c

@@ -553,7 +553,7 @@ static void nfs_direct_write_reschedule(struct nfs_direct_req *dreq)
 		/* Bump the transmission count */
 		req->wb_nio++;
 		if (!nfs_pageio_add_request(&desc, req)) {
-			spin_lock(&cinfo.inode->i_lock);
+			spin_lock(&dreq->lock);
 			if (dreq->error < 0) {
 				desc.pg_error = dreq->error;
 			} else if (desc.pg_error != -EAGAIN) {
@@ -563,7 +563,7 @@ static void nfs_direct_write_reschedule(struct nfs_direct_req *dreq)
 				dreq->error = desc.pg_error;
 			} else
 				dreq->flags = NFS_ODIRECT_RESCHED_WRITES;
-			spin_unlock(&cinfo.inode->i_lock);
+			spin_unlock(&dreq->lock);
 			break;
 		}
 		nfs_release_request(req);
@@ -871,9 +871,9 @@ static ssize_t nfs_direct_write_schedule_iovec(struct nfs_direct_req *dreq,
 
 			/* If the error is soft, defer remaining requests */
 			nfs_init_cinfo_from_dreq(&cinfo, dreq);
-			spin_lock(&cinfo.inode->i_lock);
+			spin_lock(&dreq->lock);
 			dreq->flags = NFS_ODIRECT_RESCHED_WRITES;
-			spin_unlock(&cinfo.inode->i_lock);
+			spin_unlock(&dreq->lock);
 			nfs_unlock_request(req);
 			nfs_mark_request_commit(req, NULL, &cinfo, 0);
 			desc.pg_error = 0;